/*
 *  Copyright 2008-2010 NVIDIA Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */


/*! \file transform_reduce.h
 *  \brief Dispatch layer for transform_reduce.
 */

#pragma once

#include <thrust/iterator/iterator_traits.h>

#include <thrust/detail/host/reduce.h>
#include <thrust/detail/device/reduce.h>

namespace thrust {

namespace detail {

namespace dispatch {

////////////////
// Host Paths //
////////////////
template < typename InputIterator,
         typename OutputType,
         typename BinaryFunction >
OutputType reduce(InputIterator first,
                  InputIterator last,
                  OutputType init,
                  BinaryFunction binary_op,
                  thrust::host_space_tag) {
    return thrust::detail::host::reduce(first, last, init, binary_op);
}

template < typename InputIterator1,
         typename InputIterator2,
         typename OutputIterator1,
         typename OutputIterator2,
         typename BinaryPredicate,
         typename BinaryFunction >
thrust::pair<OutputIterator1, OutputIterator2>
reduce_by_key(InputIterator1 keys_first,
              InputIterator1 keys_last,
              InputIterator2 values_first,
              OutputIterator1 keys_output,
              OutputIterator2 values_output,
              BinaryPredicate binary_pred,
              BinaryFunction binary_op,
              thrust::host_space_tag,
              thrust::host_space_tag,
              thrust::host_space_tag,
              thrust::host_space_tag) {
    return thrust::detail::host::reduce_by_key(keys_first, keys_last, values_first, keys_output, values_output, binary_pred, binary_op);
}

//////////////////
// Device Paths //
//////////////////
template < typename InputIterator,
         typename OutputType,
         typename BinaryFunction >
OutputType reduce(InputIterator first,
                  InputIterator last,
                  OutputType init,
                  BinaryFunction binary_op,
                  thrust::device_space_tag) {
    return thrust::detail::device::reduce(first, last, init, binary_op);
}

template < typename InputIterator1,
         typename InputIterator2,
         typename OutputIterator1,
         typename OutputIterator2,
         typename BinaryPredicate,
         typename BinaryFunction >
thrust::pair<OutputIterator1, OutputIterator2>
reduce_by_key(InputIterator1 keys_first,
              InputIterator1 keys_last,
              InputIterator2 values_first,
              OutputIterator1 keys_output,
              OutputIterator2 values_output,
              BinaryPredicate binary_pred,
              BinaryFunction binary_op,
              thrust::device_space_tag,
              thrust::device_space_tag,
              thrust::device_space_tag,
              thrust::device_space_tag) {
    return thrust::detail::device::reduce_by_key(keys_first, keys_last, values_first, keys_output, values_output, binary_pred, binary_op);
}

//////////////
// Any Path //
//////////////
template < typename InputIterator,
         typename OutputType,
         typename BinaryFunction >
OutputType reduce(InputIterator first,
                  InputIterator last,
                  OutputType init,
                  BinaryFunction binary_op,
                  thrust::any_space_tag) {
    // default to device path
    return thrust::detail::dispatch::reduce(first, last, init, binary_op, thrust::device_space_tag());
}

} // end namespace dispatch
} // end namespace detail
} // end namespace thrust

